This has probably come up before, but I was watching some show or other last night and I got to thinking about how the television-show-theme song has bitten the dust in the last few years (the show I was watching didn't have one). I expect it's a cost-cutting measure, but I think that's a shame, because there have been some good ones, some really iconic songs that set the stage for the show you're about watch and instantly call the show to mind whenever we hear them.
A couple of my favorites...
What's funny about this one is that I consider the sounds of the garage door, radio dispatcher and sirens at the beginning of the intro to be part of the song, but they're not. I initially did a search for "Hill Street Blues theme", but I didn't like what I found because they were missing what to me is the beginning of the song.
Similar to Hill St. Blues above, the wolf-howl is to me the beginning of the theme song, but it was actually hard to find a YouTube vid that included it, because it isn't technically part of the song.
This one is unusual in that it has lyrics, but they really preface the show for the viewer.